1. Division of Endocrinology and Metabolism and Diabetes Center, First Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
2. Clinic for Endocrinology, Diabetes and Metabolic Disorders, Clinical Centre of Vojvodina, Novi Sad, Serbia
3. Medical Faculty, University of Novi Sad, Novi Sad, Serbia
4. Diabetes Centre, Second Department of Internal Medicine, Democritus University of Thrace, Alexandroupolis, Greece